He tells eight-year-old Vera daily that she is a princess and is very pretty and cute.

He says: "Compliments contribute to how children view themselves, which builds up their self-esteem."

It is also an early eye-opener to a "fact of life" that looks are important in the real world, he adds.

He also praises his two sons, aged four and six, on their appearance - with compliments such as "the shirt looks good on you". The encouraging words acknowledge the boys' effort to make themselves presentable, he explains.

Experts agree with him on this last point, saying that appearance-oriented praise should focus on a child's effort, rather than solely on how the child looks.

For example, praise a child on the effort he took to put on a nice shirt and look tidy, suggests Ms Fiona Walker, principal of schools at Julia Gabriel Education.

Compliments such as "what a handsome boy" or "what a pretty girl" also usually flatter the parents more than the child, she adds.